This invention relates to a unique method and apparatus for monitoring brake slack adjustment in a vehicle.
A typical vehicle configuration includes several axle assemblies each with a pair of brake assemblies, one brake assembly at each wheel. The brake assemblies are typically either disc or drum type brakes and can be actuated hydraulically or pneumatically. For example, a typical disc brake assembly includes a rotating disc, an actuator, a caliper with a brake lining supported on a backing plate, and a slack adjuster for adjusting the travel distance of the caliper to the disc. The actuator moves the brake lining on the caliper into contact with the rotating disc to brake the vehicle, resulting in a temperature increase in the brake lining. As the lining wears, the distance that the caliper has to travel before it contacts the disc increases. The slack adjuster automatically adjusts the caliper such that the distance between the brake lining and the disc is optimal.
Over a period of time, slack adjusters can get out of adjustment which can result in ineffective braking. If the slack adjuster is over adjusted, the distance between the brake lining and the disc is too small which can result in the lining rubbing against the disc during non-braking conditions, and causing premature lining wear. If the slack adjuster is under adjusted, the distance between the brake lining and the disc is too large, resulting in delayed braking power. Thus, it is important to know when the slack adjusters are out of adjustment, so that they can be re-adjusted to provide optimal braking performance.